I created umd disc dumping tool to verify some question.
Related topic: http://forum.redump.org/topic/209/psp-dumping/
the PSP is accessing the data through the filesystem.. So the last sectors of a PSP dump could be erroneous and some tools are known to create bad dumps.
No problem if it uses ioctl (sceIoIoctl/sceIoDevctl).
We probably won't be able to add these dumps to Redump until there's a dumping tool that can dump both partitions at once, to ensure that there isn't a gap between them.
I tested ULJM-05105 (Stealth feat. Wipeout pure Stealth edition).
Log on GAME
pspUmdTypes: 0x30 (GAME VIDEO) L0 length: 62256 (0x0f330) 0x01F20014 is unknown: 05 80 00 32 0x01F200A0 is unknown: 20
Log on XMB
pspUmdTypes: 0x30 (GAME VIDEO) L0 length: 380304 (0x5cd90) L1 length: 431104 (0x69400) ----------------- Total: 811408 (0xc6190) 0x01F20014 is unknown: 05 80 00 32 0x01F200A0 is unknown: 20
62256 + 380304 = 442560 (it matched layerbreak). So, there isn't a gap between GAME and VIDEO.